Special features: Mark Gatiss: a study in Sherlock--30 minute "making of" documentary; Mark Gatiss: production diary; creating the look--eight inside looks into how different scenes were created in the Sherlock special; interview with the the writers Steven Moffat and Mark Gatiss; Sherlockology Q&A

Special features: Mark Gatiss: a study in Sherlock--30 minute "making of" documentary; Mark Gatiss: production diary; creating the look--eight inside looks into how different scenes were created in the Sherlock special; interview with the the writers Steven Moffat and Mark Gatiss; Sherlockology Q&A

Special features: Mark Gatiss: a study in Sherlock--30 minute "making of" documentary; Mark Gatiss: production diary; creating the look--eight inside looks into how different scenes were created in the Sherlock special; interview with the the writers Steven Moffat and Mark Gatiss; Sherlockology Q&A